Teen Scholar Names a Shrew

By Richard Stucky, PhD

At the Wind River Basin of central Wyoming, the wind does indeed blow, sometimes at hurricane gale force. The basin is at about 6,000 feet, nestled within mountain ranges completely surrounding its trapezoidal shape. These mountains began to rise about 58 to 55 million years ago and on into the middle Eocene. The mountains shed their sediments and filled the basin. More recent erosion has carved out its rocky badland landscape.

The rocks are gorgeous: layers of candy-striped light grey, light bluish, and deep red lateral horizons, yellow sandstones, and mosaic conglomerates that look like pages of a closed book, each telling a different episode in Earth’s history. They tell ancient tales of catastrophic floods, tumultuous mudflows, massive flowing rivers, expansive lake beds, and quiet backwater swamps. They also speak of an ancient tropical ecosystem with the most diverse mammalian fauna to occur in the past 100 million years.

Since the 1880s, Wind River has been a hunting ground for fossils that span the bridge between the early and middle Eocene (52 to 49 million years ago) when the climate was some 20° F warmer annually than today. Over the years, paleontologists from across the country have trekked the basin looking for fossils of ancient primates, horses, and tapirs; small even-toed ancestors of today’s cows, pigs, antelope, and bison; and primitive insectivores. Thousands of specimens have been collected.

I began working one of the basin’s sites, the Buck Springs Quarries, while I was at the Carnegie Museum of Natural History in the early days of my career. Since joining our Museum in 1989, I have continued exploring this site, collecting hundreds of specimens that are now in the Museum’s collections. When the Teen Science Scholars program for high school students began in 2007, I realized that Buck Springs would be a perfect location for the teens to conduct authentic scientific research.

We had seven students the first year of the program, including Michael Christiansen. He has a keen eye for fossils and a passion for science. He was then in his final year of high school, and he decided to study some of the Wind River fossil insectivores for his senior thesis. These nyctitheres are a group of tiny animals with jaws only a couple of centimeters long. Michael and I then joined forces to study the entire group of nyctitheres found in North America. We discovered that the Buck Springs sample contained two new species and a new genus. One of the species was discovered by the Teen Science Scholars, and it was different, more primitive, and completely unknown.

Paul Rosen has long been a volunteer helping us hunt fossils in the Wind River Basin. Paul and his wife, Harriet, donated the seed money for Teen Science Scholars and helped select the first class of scholars. In honor of the Rosens’ generous support, Michael and I named the new animal Acrodentis rosenorum. The fossils may have been an ancestor or a close relative of modern shrews. Weighing only a few grams, they scampered in the underbrush on the wet forest floor of the rich tropical rainforest, hunting down small insects and invertebrates.

Teen Science Scholars has flourished since its founding by the Rosens. This past summer, 30 students worked in the field and onsite at the Museum. The scholars conducted authentic research that they presented during a poster session. Through the generous support of the Rosens, the Hugh and Michelle Harvey Foundation, John and Suzanne Oró, Lee and Susan McIntyre, and Newmont Mining, more than 75 students have participated in the program, encouraging their interest in science and preparing them for potential careers in science. There is little doubt that future paleontology scholars will find many more new ancient animals and plants. Although today Michael is a PhD graduate student in materials science and engineering at MIT, he still joins us each summer during his “vacation” to discover more ancient 50 million-year-old fossils.

Photo: Michael Christiansen (right), a graduate of the Teen Science Scholars program, works alongside Teen Scholar Marc Thomson at the Wind River Basin in summer 2013.

Dr. Richard Stucky is curator of paleoecology and evolution. Find out about his research @ www.dmns.org/science/museum-scientists/richardstucky/. This fall, Stucky and former Teen Scholar Michael Christiansen published their naming of Acrodentis rosenorum in the Annals of the Denver Museum of Nature & Science. Find it @ www.dmns.org/science/museum-publications/. Find out more about Teen Science Scholars @ www.dmns.org/sciencescholars.

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